Verify Email address (Not just syntax)

Question

Is there any software in Ubuntu that can verify email address (not syntax, email exists or not). I need a software or script or anything to check whether an email address exists or not (not email syntax).

Answer 1

If you really need to verify that the address is valid you need to send a message, and get an appropriate response. This is commonly done by embedding a link to a web page which completes the address verification.

Verifying addresses prior to actual delivery can be unreliable.

• Many servers will detect hosts are verifying addresses and begin falsifying results, or start classifying their email as spam.
• Other sites accept all mail to their domain and simply drop invalid addresses. The ratio of dropped addresses to real addresses can be used to classify the sender a spam sender.

Checking that the domain portion of the address has an MX is a good validity check. A few valid email addresses may have an A record without an MX record, but most of these domains will be invalid. The syntax of the user portion of the address can be validated. A simple syntax check works in most cases, especially if you limit only accept the routing portion of the address. Addresses like "Some user" <someuser!host#otherhost@example.com> are more difficult to handle.

I have run a periodic validation script on user's email addresses. This did do validation by connecting to the mail server and validating the recipient. This was done with a limited set of domains from a trusted domain. Some domains had to be handled as special cases as they would give high rates of false positives or false negatives. In either case, the validation call-out was disabled for that domain.

Answer 2

To verify that an email recipient really exists you have to send a message to the server, if you get no return the user exists, else you get your email back with an error message.

There is no other way of doing this, there are so many mail servers out there that even if one server supported this option that would not mean all of them would.

Not much you can do :(

There are scripts (as you know) that verify syntax and force you to double check it but the true verification comes in the form of a email sent to that address to verify if it exists and to verify that the user inputted an email address of his own.

Ofc you can use an library that checks if the server exists (like libmail-verify), but to check if a user exists that is another issue.

Answer 3

apt-cache search email | grep verify returns libmail-verify-perl

After installing it check the man page for details, should be exactly what you need.